Initial revision

lib/syslib/kputc.c

@@ -0,0 +1,47 @@
+/* A server must occasionally print some message.  It uses a simple version of 
+ * printf() found in the system lib that calls kputc() to output characters.
+ * Printing is done with a call to the kernel, and not by going through FS.
+ * This way system messages end up in the kernel messages buffer and can be 
+ * reviewed at a later time. 
+ *
+ * This routine can only be used by servers and device drivers.  The kernel
+ * must define its own kputc(). Note that the IS also defines its own kputc()
+ * to directly call the TTY instead of the kernel, because it does not want
+ * to pollute the kernel message buffer with its debug dumps. 
+ */
+
+#include "syslib.h"
+#include <minix/callnr.h>
+#include <minix/minlib.h>
+
+/*===========================================================================*
+ *				kputc					     *
+ *===========================================================================*/
+void kputc(c)
+int c;
+{
+/* Accumulate another character.  If 0 or buffer full, print it. */
+
+  static int buf_count;		/* # characters in the buffer */
+  static char print_buf[80];	/* output is buffered here */
+  message m;
+
+  if ((c == 0 && buf_count > 0) || buf_count == sizeof(print_buf)) {
+	/* Send the buffer to the system task, or, if this process is not a
+	 * server yet, to standard error.
+	 */
+	m.DIAG_BUF_COUNT = buf_count;
+	m.DIAG_PRINT_BUF = print_buf;
+	m.DIAG_PROC_NR = SELF;
+	m.m_type = DIAGNOSTICS;
+	if (_sendrec(TTY, &m) != 0) {
+		m.m1_i1 = 2;
+		m.m1_i2 = buf_count;
+		m.m1_p1 = print_buf;
+		m.m_type = WRITE;
+		(void) _sendrec(FS, &m);
+	}
+	buf_count = 0;
+  }
+  if (c != 0) print_buf[buf_count++] = c;
+}